In connection with surgery for a number of diseases in the gastro-intestinal tract a consequence is in many cases, that the colon, the ileum or the urethra has been exposed surgically. The patient is left with an abdominal stoma and the effluents or waste products of the body, which are conveyed through these organs, are discharged through the artificial orifice or opening and are collected in a collection bag. The bag is usually adhered to the skin by means of an adhesive wafer or plate having an inlet opening for accommodating the stoma.
Often a paste is used for filling an area between the stoma and the skin barrier in order to provide a safe seal, or building up an irregular abdominal skin area around the stoma to achieve a smooth surface onto which an appliance can be securely attached.
Such pastes should have a composition which makes it sufficiently tacky to attach safely to the skin on an immediate basis, easily shaped by finger pressure, and removable in one piece without leaving residues. Furthermore, the composition should be skin friendly, have a high moisture absorption level and a high erosion resistance in order not to expose the skin to exudates from the stoma.
Ostomy pastes are commercially available in the form of sticks/strips or rings, for example Coloplast ostomy paste, Eakin® ring, Stomahesive© paste marketed. International Publication No. WO 98/17329 describes a mouldable mass of hypoallergenic, substantially non-memory putty-like adhesive for use in connection with fistulas or ostomy appliances. The composition comprises 1-20 wt. % of a block copolymer having a major content of di-block copolymer, 5-60 wt. % of a tackifying liquid constituent and 1-10 wt. % of a waxy constituent.
Eakin Cohesive®, a hydrocolloid product available from TG Eakin Limited is said to be a mouldable, easily shaped, moisture absorbing skin barrier. According to information extracted from the Eakin website, http://www.eakin.co.uk, it can be stretched, compressed or moulded to fit the exact shape and size as required. Eakin Cohesive contains no active ingredients but is said to contain a unique carbohydrate which is slowly released while the seal is in place, diluting harmful enzymes, and protecting the skin against body wastes and fluids such as bile and ileal fluid. The product can be used as a seal under stoma pouches and appliances, as a packing agent in skin folds and scars, as a seal around drain tubes and fistulae, and as a “picture frame” around wound edges prior to dressing application.
These pastes suffer from two essential drawbacks:
1. In order not to remember its original shape (non-memory), the pastes have a high level of plasticity. However, after use it is desirable to be able to remove the pastes in one piece without leaving a large amount of, hard to cleanse, residues on the skin. For that reason a high volume of particles in the form of hydrocolloids are added not only in order to achieve the desired moisture absorption rate and capacity, but also to make the shape of the pastes stabile during use and minimise residue left on the skin after removal. The high volume of particles makes the paste harder, and for end-users it requires a certain amount of finger/hand strength. It is often time consuming to shape the pastes to fit the skin.2. The pastes have high moisture absorptions in order to achieve optimum adhesive performance and maintain a healthy skin. However, the necessary absorption level combined with the level of plasticity needed for the pastes to be non-memory like, means that it will disintegrate easily due to the swelling of the hydrocolloids when in contact with exudates. The poor erosion resistance makes the service life short, promotes leakage and/or makes the skin of the users exposed to contact with aggressive output, leading to skin issues.
As a method of improving the erosion resistance of hydrocolloid adhesives the use of cross-linked hydrocolloids is described. Cross-linked hydrocolloids (for example carboxymethyl cellulose (CMC), dextrane) will not dissolve due to the cross-linked structure. During the swelling process, the individual particles will therefore obtain a gel like structure, but no coherent gel can be formed since molecules in the cross-linked materials are locked in a network constituting individual particles. However, in contact with exudates, the cross-linked hydrocolloids will be leached out due to the lack of a cohesive gel, and the effect on the erosion resistance is therefore limited.
Another method is increasing the cohesion of the continuous phase. Thereby the continuous phase will be less prone to disintegration during the swelling of the hydrocolloids. The drawback of utilising this method is that the increased cohesiveness will reduce the absorption rate, and ultimately a deficiency in plastic deformation will make the paste lose contact with the skin and exposing it, due to excessive swelling in the contact with exudates.
It has now surprisingly been found that by utilising a soft permeable composition, a paste can be produced that is easier to shape and has improved erosion resistance, without compromising the moisture absorption, ease of removal or introducing other possible adverse effects.